There are many instances where it is necessary or desirable to change a lock so that previously operable keys are no longer effective to unlock the door. This is particularly important in offices and other commercial installations where periodic rekeying of the lock is desired to prevent unauthorized access by persons, such as former employees, or others, who have acquired keys to the relevant doors. Such alteration of the lock is made much simpler where the lock is an interchangeable core lock. An example of a commonly accepted interchangeable core lock is illustrated in the Schlage Lock Company's U.S. Pat. No. 4,123,926. Such interchangeable core locks allow the locksmith to prepare a set of lock cores keyed to a new key at his shop; the newly rekeyed lock cores can then be inserted into the locksets at the worksite. This method is more efficient than requiring the locksmith to do the rekeying of each lock while on location at the worksite.
A known device for use in disassembly of a interchangeable core cylinder lock is described in U.S. Pat. No. 4,680,860 to Detloff. The device described in the patent is designed to allow the locksmith to discover the control key codes for the lock by allowing the locksmith to capture the pins, in their correct sequence, which are removed from a lock core. The pins are captured in a series of pin retaining chambers, one for each pin. In practice, it has been found that this device is tedious to use, as it requires an overly complicated series of steps to mount the lock core into the core receiving channel. Specifically, it is necessary to pivot the members of the device together and lock them together using a latching means, whereupon, the lock core may be inserted into a channel formed between the two members, and is then secured with a set screw. Removal of the lock core from the device requires the opposite series of steps, including, releasing the set screw, carefully sliding the two members relative to each other to release the latching mechanism, and pivoting the members apart so that the core can be removed from the channel. The core must then be transferred to another device for repinning the core with new lock pins and for capping the lock with the necessary cap to retain the newly installed lock pins.
Another known device is used simply for removal of pins. In these devices, a block is provided with a channel of a cross-sectional shape suitable for confining a lock core (such as a Figure "8" in cross-sectional shape for Schlage.RTM. lock cores) machined into the top of the block. The channel thus has an open upper end. A series of bores extend perpendicularly from the channel downwardly to a hollowed out dump area in the block. A lock core can be mounted in the block by sliding it into the channel, in an upside down orientation, so the lock pins can be removed from the lock core by punching them out from the upwardly facing lower face of the lock core with an ejector pin.
A device for the repinning and recapping of pins is a similar block with a core holding channel (for example, with a Figure "8" cross sectional shape). One or more tops may be provided to the channel in this device so that the channel is completely enclosed within the block without any open upper end. The tops have a plurality of pinning bores extending from the upper outer surface of the block to the core holding channel. This block is used for the repinning and recapping of an interchangeable core by sliding the lock core into the passage in an upright orientation, so that lock pins can be dropped through the pinning bores into the lock core at the correct locations. A lock cap (a curved metal cover) is then pressed into place in the lock core to hold the newly installed lock pins in place.